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120-130mm Refractors for Visual and Possibly EAA - Go Budget or Expensive?

refractor observing
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#1 Spacefreak1974

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Posted 23 September 2019 - 11:42 AM

It seems I could get the well-loved Skywatcher 120ED/Evostar 120ED used for under $1000 and then grab a Moonlite Focuser for it and have a really great scope...probably all in for under $1200 if purchased used on the scope

 

Or could get the Astro-Tech 130 Triplet for under $1900 and it now comes with a nice hard sided case

The FPL53 TS130 which appears to be the same "chassis" would likely be same cost as delivered but not include a case

 

Or could wait on a used Takahashi 128 or 120 triplet, but not sure if I could nab either for under $3000

 

Jon



#2 kecked

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Posted 23 September 2019 - 12:06 PM

go with the astrotech 127 and spend the rest on a good mount.  I have the 102 and it's a really good scope though I wish it was larger.  I have a meade AR 6"  and it's good too but color fringes and size prevent me from pulling it out to use.  a 127 is just right.



#3 BravoFoxtrot

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Posted 23 September 2019 - 12:57 PM

I’ve long had this internal debate.  The issue I have with this aperture in refractors is that the inconvenience is often exceeded by the performance.  One could easily out perform a premium 5” APO with a modest reflector or SCT...at a fraction of the cost.  Refractors don’t scale well in my opinion.  To achieve similar performance of other designs, everything is bigger.  Bigger cost, bigger size, bigger mount, bigger weight, bigger inconvenience...bigger everything for a sometimes marginal performance increase.  

 

Just my $.02 (if it’s worth that), but if I went with a 5” or 6” refractor, I’d likely go a less expensive route in an attempt to maximize my performance/cost ratio.  

 

This is only my opinion and I’m sure others disagree.  And rightfully so, individual requirements vary significantly.


Edited by BravoFoxtrot, 23 September 2019 - 01:00 PM.

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#4 Auburn80

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Posted 23 September 2019 - 01:12 PM

go with the astrotech 127 and spend the rest on a good mount. I have the 102 and it's a really good scope though I wish it was larger. I have a meade AR 6" and it's good too but color fringes and size prevent me from pulling it out to use. a 127 is just right.


Did you mean the AT130EDT? Or is there a 127?

#5 Spacefreak1974

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Posted 23 September 2019 - 01:51 PM

Let me clarify some things

 

Reason

-I'd like to have a refractor to gain some sharpness over my 8" SCT and be used to compliment the SCT and potentially have a quicker deploy grab and go on a manual mount

 

Assume the mount will be either an iOptron AZ Mount Pro or CEM40 and be used primarily for visual. I also may use said refractor on a GSO Skyview Deluxe with an upgraded tripod for more of a quick deploy grab and go

 

Also i'm not a newtonian fan and know that I could get a large newtonian, but they are not my preference. The newtonian i'd have to buy to justify a change would be a premium unit costing more than what i'm willing to spend here. Try not to read into this to much and i'm not trying to start a quarrel with the Dob lovers

 

Jon



#6 bobhen

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Posted 23 September 2019 - 02:04 PM

The TS 130 uses FPL 53 for better color correction. The AT 130 does not.

The SW 120 is a doublet.

So, how important is imaging?

 

When buying a refractor (and 120 -130mm refractors are small telescopes) you have already given up aperture so “very high” optical quality (sharpness and contrast) is what you want and what you should be paying for and getting. And it is why some refractors are better (and more expensive) than others. Otherwise, with the same money, you could get (and have) a larger mirror scope.

 

If you want all of that refractor sharpness and contrast goodness, then place a wanted ad for a Takahashi and see what turns up. Just getting “a refractor” does not mean you will get the sharpness and contrast that refractors are famous for.

 

Bob


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#7 Jon Isaacs

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Posted 23 September 2019 - 02:12 PM

To add to what Bob said:

 

Budget versus expensive:

 

A budget 120mm refractor is the 120mm F/8.3 achromat. They're around $200 used, I bought one in decent shape for $50. 

 

Expensive is anything with real ED glass.  

 

When I was faced with this question, I looked at the various 120mm and 127mm - 130mm ED/apos and decided the larger scopes were just too big to be grab and go.. I liked the size and weight of the 120mm Skywatcher but not the build.  I settled on a used 120mm Orion Eon, the same 120mm F/7.5 FPL-53 optics but a nice quality build.  

 

It's handy but it doesn't take a premium Dob to do the number on it.  Such are the virtues of aperture.  

 

Jon


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#8 bobhen

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Posted 23 September 2019 - 02:22 PM

Let me clarify some things

 

Reason

-I'd like to have a refractor to gain some sharpness over my 8" SCT and be used to compliment the SCT and potentially have a quicker deploy grab and go on a manual mount

 

 

Jon

After reading this post of yours, I would consider the new Takahashi FC 100DZ

 

It will have killer optics
Really be an easy & quick set up
Easy to use on just about any alt/az mount
It’s a doublet for quick acclimation
Casual imaging is more than doable
Should fall within your budget
Also great for solar
Seems to check all of your boxes

 

Don’t worry about aperture; you have the C8 for that.

 

Bob



#9 areyoukiddingme

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Posted 23 September 2019 - 02:24 PM

A couple of thoughts . . . 

 

If you think you will have the hankering for the premium scope, you might be better to search for that as you'll only get there in the end anyway. If you are on the fence, I'd say used Skywatcher 120 is the way to go.

 

Otherwise, the Takahashi TSA 120, I'd probably take my chances and buy from Japan or Hong Kong,

 

e.g., http://www.tan14.com...st/10-Takahashi

 

But I also think a 5" refractor is not so much of a complement to an 8" SCT. They are going to be reasonably close in performance. In which case, perhaps a smaller refractor is the better option.


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#10 ris242

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Posted 23 September 2019 - 02:28 PM

Wow a visual and EAA thread and all of a sudden the only options are Taks.

Who would have thought?


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#11 Spikey131

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Posted 23 September 2019 - 02:30 PM

Let me clarify some things

 

Reason

-I'd like to have a refractor to gain some sharpness over my 8" SCT and be used to compliment the SCT and potentially have a quicker deploy grab and go on a manual mount

 

Assume the mount will be either an iOptron AZ Mount Pro or CEM40 and be used primarily for visual. I also may use said refractor on a GSO Skyview Deluxe with an upgraded tripod for more of a quick deploy grab and go

 

Also i'm not a newtonian fan and know that I could get a large newtonian, but they are not my preference. The newtonian i'd have to buy to justify a change would be a premium unit costing more than what i'm willing to spend here. Try not to read into this to much and i'm not trying to start a quarrel with the Dob lovers

 

Jon

A 5” refractor will compete with an 8” SCT more than complement it.  It will not be easier to deploy, in fact I think it will be harder to deploy.

 

A 5” refractor will be at (my) upper limit of weight and moment arm on the mounts you mention. Have you considered a 4” APO instead?  These are a lot more manageable than a 5”.

 

If you go with the AZ Mount Pro, you can mount them together:

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#12 Spacefreak1974

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Posted 23 September 2019 - 02:33 PM

The TS 130 uses FPL 53 for better color correction. The AT 130 does not.

The SW 120 is a doublet.

So, how important is imaging?

 

When buying a refractor (and 120 -130mm refractors are small telescopes) you have already given up aperture so “very high” optical quality (sharpness and contrast) is what you want and what you should be paying for and getting. And it is why some refractors are better (and more expensive) than others. Otherwise, with the same money, you could get (and have) a larger mirror scope.

 

If you want all of that refractor sharpness and contrast goodness, then place a wanted ad for a Takahashi and see what turns up. Just getting “a refractor” does not mean you will get the sharpness and contrast that refractors are famous for.

 

Bob

Imaging not so much, but would like to try out EAA possibly. 



#13 Spacefreak1974

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Posted 23 September 2019 - 02:35 PM

A 5” refractor will compete with an 8” SCT more than complement it.  It will not be easier to deploy, in fact I think it will be harder to deploy.

 

A 5” refractor will be at (my) upper limit of weight and moment arm on the mounts you mention. Have you considered a 4” APO instead?  These are a lot more manageable than a 5”.

 

If you go with the AZ Mount Pro, you can mount them together:

NP101?



#14 MalVeauX

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Posted 23 September 2019 - 02:45 PM

Heya,

 

A big 5" triplet will take a while to cool, just like your SCT. A 5" triplet will not be good on a Skyview Deluxe mount likely. They're heavy ~20lb scopes.

 

Since your goal is faster deployment and you want to use a manual mount sometimes and compliment your SCT, I would look at:

 

Skywatcher PRO ED100 F9 (FPL53 glass)

T.S. 102mm F7 APO (FPL53 glass)

T.S. 102mm F11 ED

 

Very best,


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#15 SeattleScott

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Posted 23 September 2019 - 03:05 PM

I use a Vixen ED103S for visual and EAA with Mallincam. Have a flip diagonal to switch back and forth. I use a cheap reducer 1.25” thread on for the camera to get it around F5.4. Same as NP101 but much cheaper. Reducer probably not as high quality but EAA isn’t generally very high resolution anyway.

An AT130 with appropriate mount is a bit of a beast.

Scott

#16 areyoukiddingme

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Posted 23 September 2019 - 03:53 PM

Wow a visual and EAA thread and all of a sudden the only options are Taks.

Who would have thought?

The title of the thread asks for both budget and expensive options.

 

Last I checked, Takahashi's qualify as 'expensive' for most people.

 

I also suggested a Skywatcher 120, and to consider a 4". . .so, no, Taks are not the only options being suggested.


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#17 Spikey131

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Posted 23 September 2019 - 04:22 PM

NP101?

Yes.  A little heavy for the secondary saddle on that mount, but it works if you keep everything balanced.



#18 Jond105

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Posted 23 September 2019 - 04:30 PM

Definitely go with the 120ED. But that’s my biased opinion to anyone whoever asks. Especially if you’re already thinking of a moonlite upgrade. 

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#19 Jond105

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Posted 23 September 2019 - 04:31 PM

I’m up and running in under 5 minutes in this configuration. Balanced and all. 

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#20 YAOG

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Posted 23 September 2019 - 04:55 PM

Hi Jon,

 

If you want a lighter quick cooling refractor with excellent sharpness, contrast and good color correction I recommend the best quality used 100mm - 120mm doublet which uses an FPL-53 ED element you can afford and no faster than f/7 and f/9 is even better for color correction. There will be people that tell you to not get hung up on the ED glass type used and try to tell you an FPL-51 or equivalent ED glass is just as good but in fact this is almost never the case with budget lenses. Maybe a very long slow premium FPL-51 scope will get close but all things being equal it is impossible due to physics. 

 

So as far as light gathering and quality of the views at the eyepiece goes as someone else mentioned a good 130mm class refractor is more a peer of an 8" SCT in many ways other than light gathering. To complement an 8" SCT IMO a better mate than a 125mm-130mm refractor is a 100mm f/7 -f/9 ED refractor which puts up widefield views with delightful pinpoint stars on a dark background especially in a light polluted area where a larger aperture can be a hindrance. IMO 100mm is enough glass to see moderately bright objects and still portable if a bit longer than your 8" SCT. 


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#21 drd715

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Posted 23 September 2019 - 05:43 PM

Heya,

A big 5" triplet will take a while to cool, just like your SCT. A 5" triplet will not be good on a Skyview Deluxe mount likely. They're heavy ~20lb scopes.

Since your goal is faster deployment and you want to use a manual mount sometimes and compliment your SCT, I would look at:

Skywatcher PRO ED100 F9 (FPL53 glass)
T.S. 102mm F7 APO (FPL53 glass)
T.S. 102mm F11 ED

Very best,

Three different and interesting scopes.

127/130mm is a nice all around scope. I had a 127-f8 achro for many years. It was very sharp in focus. But as achro's tend to be it wasn't the best on bright objects such as moon and planets. Great at lower powers. Just fun.

For visual personally I would not go below 100mm unless you want to use it for wider field low power use. As the longer FL higher F# refractors in smaller diameter objectives can get a bit dark in the visual view.

The TS F-11 is a very interesting scope, but as an only scope it is more useful as a moon/planetary visual observer than an overall use scope. I would like to have one though. Good value.

The shorter TS triplet would probably be a very good quick grab scope. It should be very sharp and nearly color free.

The 100ed f-9 is a nice scope a bit long, but not as long as the TS-f11. Good optics, but a bit underwhelming mechanically, the focuser in particular could be a lot better.

I think the TS triplet scopes come in a 115mm version as well as a 130mm.

A few things to consider in a scope choice of this general size; first what objects are you going to try to view and how wide are they.

For planets you don't want to be too short or you won't see much detail. 1000+mm fl. The problem is 1000mm fl requires a substantial mount and its associated weight. Maybe not the best grab & go.

The shorter APO triplets have the advantage as a quick use scope. A good mount is necessary, but you could use an HEQ-5 instead of an Atlas EQ6. Or even a light weight alt/az simple mount for that ultra light grab&go. I would favor the 115's in this range shorter triplet scopes. Say around 600/700mm FL. They would probably work for imaging too.

Field of view and light gathering power are really target object specific. And some objects will just require more aperture than is cost and size practical in a refractor. So ask yourself what it is that you want to look at. Then match the scope to it. You will probably find that you need a pair of binoculars and 3 different scopes (and probably 2 mounts)(not to mentionthe number of eyepieces).

Just remember to purchase quality at a reasonable value. Doing so will retain the resale value and you will find your astro stuff will not devalue much and it will be sought after on the preowned market when you want to upgrade. I like to buy gear on the cn classifieds as you can usually get it for 1/3 off new price or better. But some of the rarer greatly sought after items may hold their new price value very well. Might even be at a premium. You just have to have a clear picture of what you really want.

Have fun.

Sent from my SM-N950U using Tapatalk

#22 bobhen

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Posted 23 September 2019 - 05:57 PM

Imaging not so much, but would like to try out EAA possibly. 

You can use your 8” SCT for EAA. Astro video with a C8 and the Revolution 2, $299 video camera with a reducer will produce astounding bang-for-the-buck results.

 

SCTs are really great for EAA: you don’t need high quality optics, they can be reduced and made quite fast and with their moving mirror SCTs don’t have focus issues.

 

I used a C11 with a video camera for 15 years and it was a great combination.

 

Any of the refractors mentioned will also be fine for EAA but with your SCT, you don’t need one to try it.

 

Bob


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#23 213Cobra

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Posted 23 September 2019 - 06:53 PM

>>For visual personally I would not go below 100mm unless you want to use it for wider field low power use. As the longer FL higher F# refractors in smaller diameter objectives can get a bit dark in the visual view.<<

 

I have 51mm to 160mm in aperture. They are all equally engaging but optimal for different circumstances and perspectives. RIght up to the point where a small aperture scope + eyepiece becomes too dark, the view can be nevertheless sensational. My solution to the larger aperture appeal has been flat field refractors up to ~4" (in my case, 4.17") and a corrected fast Newtonian at 6.3"/160mm. The 6.3" is compact for its aperture, reasonably light and balance; rock solid and maneuverable on a DM6 or EM100 EQ.

 

Phil



#24 Jon Isaacs

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Posted 23 September 2019 - 08:19 PM

Hi Jon,

 

If you want a lighter quick cooling refractor with excellent sharpness, contrast and good color correction I recommend the best quality used 100mm - 120mm doublet which uses an FPL-53 ED element you can afford and no faster than f/7 and f/9 is even better for color correction. There will be people that tell you to not get hung up on the ED glass type used and try to tell you an FPL-51 or equivalent ED glass is just as good but in fact this is almost never the case with budget lenses. Maybe a very long slow premium FPL-51 scope will get close but all things being equal it is impossible due to physics. 

 

So as far as light gathering and quality of the views at the eyepiece goes as someone else mentioned a good 130mm class refractor is more a peer of an 8" SCT in many ways other than light gathering. To complement an 8" SCT IMO a better mate than a 125mm-130mm refractor is a 100mm f/7 -f/9 ED refractor which puts up widefield views with delightful pinpoint stars on a dark background especially in a light polluted area where a larger aperture can be a hindrance. IMO 100mm is enough glass to see moderately bright objects and still portable if a bit longer than your 8" SCT. 

 

I pretty much agree with what you.  The reality is that in a doublet, FPL-53 will provide significantly better color correction. 

 

I personally find the 120mm F/7.5 FPL-53 is a nice balance between portability and capability,  It's enough more capable that a 100mm viewing the planets and double stars to make the relatively small added effort worthwhile.  I don't really see the sky brightness as an issue, it's a function of exit pupil so a modest 20% increase in magnification equalizes the sky brightness between a 100mm and a 120mm.  From my backyard, I prefer the 120mm.

 

The 120mm Eon weighs 15.2 pounds with a diagonal, rings and a dovetail, ready to go, I use it with a StellarVue MG-2 mount, very solid, it weighs 19 pounds so I am looking a relatively easy 34 pounds to carry out the backdoor. 

 

Eon Number 2 Backyard 1.jpg

 

In a comparison with an SCT or Newtonian, the advantage of the refractor is that it just works, the thermal issues are minimal compared to the other two.  I can carry the refractor outside and it's giving very good images without having to wait.  

 

Jon


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#25 scooke

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Posted 23 September 2019 - 08:45 PM

If you're set on a refractor, I would recommend the Stellarvue 125 Access.  I have one and they have great optics and mechanical including the focuser and last I checked they still have some at the $1495 closeout price.  Another option is get an Edge 8.  Really nice optics and more aperture but you do have to deal with thermal issues more than the refractor.  


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